Fecal Shedding of Multidrug Resistant Isolates in Dogs Fed with Raw Meat-Based Diets in Brazil.

The practice of feeding dogs raw meat-based diets (RMBDs) is growing in several countries, and the risks associated with the ingestion of pathogenic and antimicrobial-resistant in dogs fed these diets are largely unknown. We characterized strains isolated from dogs fed either an RMBD or a conventional dry feed, according to the phylogroup, virulence genes, and antimicrobial susceptibility profiles of the bacteria. Two hundred and sixteen strains were isolated. Dogs fed RMBDs shed strains from the phylogroup E more frequently and were positive for the heat-stable enterotoxin 1-encoding gene. Isolates from RMBD-fed dogs were also frequently positive for multidrug-resistant isolates including extended-spectrum beta-lactamase (ESBL) producers. Whole-genome sequencing of seven ESBL-producing strains revealed that they predominantly harbored , and two strains were also positive for the colistin-resistant gene . These results suggest that feeding an RMBD can affect the dog's microbiota, change the frequency of certain phylogroups, and increase the shedding of diarrheagenic . Also, feeding an RMBD seemed to be linked with the fecal shedding of multidrug-resistant , including the spread of strains harboring mobilizable colistin resistance and ESBL genes. This finding is of concern for both animal and human health.